SILICONE AND RUBBER PARTS STORAGE

On 05-02-2013

ALL YOU HAVE TO KNOW ABOUT ELASTOMERS PARTS STORAGE

NF 47507 norm recommendation:
"Packings must be light proof and stocked in a fresh, dry, and not dusty area."

Temperature
Temperature to be between +5° C and +35° C.
Physical properties modifications can occur mainly due to higher temperatures (above 30° C). Beware of heat sources close to the stocking area !

Low temperatures are not likely to interfere rubber parts quality. But a few elastomers can become very stiff with low temperatures (- 40° C and beyond). They must be brought back to normal temperatures during a few hours before being used or mounted.

Humidity
best humidity value is between 45 and 70 %.

Light
Elastomer parts must be protected from light : sun beams, artificial lights rich with UV or ozone (fluorescent light tubes).
Cardboard or plastic boxes are recommended.

Oxygen and ozone
Stocking conditions must prevent elastomer parts against fresh air. Stocking area must not be close to an equipment producing ozone, or fluorescent tubes, mercure lights, electric motors or equipment producing sparks.

Thinners, petrol, chemical producs, acids must not be stores in the same area.

Deformation
Make sure not to store elastomer parts in non rigid packings or boxes.
Parts deformation could prevent a correct use and mounting, or lead to bad function.

Stocking duration
There is no norm related to this question.
According to matelials, following evaluation is possible:
3 years for NR, SBR
8 years for NBR, CR, AU/EU, NBR/PVC…
15 years for silicone EPDM, FPM, FMVQ, HNBR, VMQ, LSR, AEM, ACM…
Maximum stocking in the best conditions mentioned here above